1. Field of the Invention
The present invention relates generally to a luminous electric display unit of the inert gas-containing tube type. More particularly this invention is directed to a luminous electric display unit wherein the tube is partially protected with a transparent trough that is visible from all sides of the sign.
2. Description of Related Art
Luminous electric signs of the inert gas-filled tube type have long been employed in commercial and business establishments to provide decoration and/or impart information. Typically, such signs are referred to as "neon signs" and may be hung or placed in various locations, such as storefront windows, to advertise a product, decorate, or provide message information.
The tubular lighting elements of the sign may be conformed into an array of desired letters, logos, symbols, or decorative shapes, as in a glass tube-bending operation. The array is supportably attached by suitable brackets or wires to a rigid open frame, to a support backing, or to some form of housing or box.
In some situations, the housing that supports the lighting elements takes on special importance. For example, in applications such as food service, health care, schools, or any function involving children, safety is a primary consideration. When used in food service settings, the dust, foreign particles, and insects that tend to accumulate in neon signs become more than a mere nuisance, they may pose a contamination threat to food products in proximity. Luminous neon tube type signs, with their bright and varied colors, frequently draw the attention of children and can thus prove problematic because children are tempted to reach for the thin glass tubing. Moreover, governmental entities often place regulations on the use of luminous neon tube type signs in the above applications to guard against injury should the glass tubing break.
Security is another factor that retailers often consider when choosing a sign for advertising in and around their businesses. Many business owners want to maintain unobstructed sight lines to critical areas of their store or property to minimize opportunities for theft or other undesirable activity. Luminous neon tube type signs generally block the sight lines with their housing and thus are not used when unobstructed views are required.
As true of any product, manufacturing expense is always important. Housing for the components of a luminous neon tube type sign usually comes in multiple parts that must then be assembled. The additional assembly cost can add significantly to the manufacturing cost of the sign.
Various types of neon signs are known and found in the prior art. U. S. Pat. Nos. 1,570,980 to Wiegend, and 1,872,428 to Drury, show neon tube type signs where the glass tube is embedded in a groove to form the outline of a character or symbol. U. S. Pat. No. 5,267,404 to Kizy shows a neon tube type sign where the glass tube is mounted on a face plate that is in turn recessed within a rectangular housing. However, none of these signs completely cover the neon tube to protect the glass tubing from damage and to protect the public from injury. Kizy shelters the glass tube by placing the display unit within the housing, but the glass tube is still accessible from the front of the sign. U. S. Pat. No. 1,917,956 to Earley discloses a neon tube type sign where the glass tube is embedded in plaster and wax. While the plaster provides strong support for the tube, the front side of the tube is still exposed to the elements and thus may be soiled with insects, dust, and other foreign materials.
In addition, all of the above signs will block the sight lines wherever they are used and thus are not preferred where security is important.
None of the above signs use a single unit of material to totally encapsulate the glass tubing. Although Earley embeds the tubing in plaster and wax, the manufacturing process requires the plaster to be etched away in front of the tubing thus requiring a labor intensive step that defeats the benefits of complete encapsulation.
In view of the above, and in accordance with the present invention, it is desirable to provide a luminous electric display unit of the inert gas-filled tube type that protects both the glass tubing and the public from harm and keeps the glass tubing free from foreign debris. It is also desirable to provide a luminous electric display unit that is substantially transparent to allow for greater visibility of activities taking place in and around a place of business, for example. In addition, it is also desirable to reduce assembly expense by forming the housing from a single unit of material that encapsulates the glass tubing and is then sealed.